Let-off mechanism for looms



Feb. 8, 1938. GRENlER 1 2,107,696

LET-OFF MECHANISM FOR LOOMS Filed July 31, 1937 2 Sheets-Sheet 1 Inventor ,4 fiorneys Feb.8, 1938. I GRENlER 2,107,696

LET-OFF MECHANISM FOR LOOMS Filed July 31, 1957 2 Sheets-Sheet 2 Inventor Attorneys Patented Feb. s, 1938 s PATENT OFFICE LETf-"OFF'MECHANISMFOR LOOMS Arthur Grenier, Lawrence, Mass. Application July 31, 1937; Serial 'Niv. .15e, so4

i 2 Claims. (01. 188-83) My invention relates to improvements in letoif mechanism forlooms and the primary object thereof is the provision of an efiicient, simply constructed and inexpensive mechanism for imposing braking tension in variable degree against the warp beam of a loom and within a wider range of variation than can be accomplished with present day mechanisms of this character.

The invention also comprehends other objects,

subordinate in character, all of which together with the precise nature of my improvements will l be'readily understood when the following description and claims are read with reference to the drawings accompanying and forming part of this specification. In said drawings:-

Figure l is a fragmentary view in side elevation of aportion of a loom equipped with my improved let-off mechanism,

mechanism,

Figure 3 is a view in top plan of a link form- 7, ing an extension for said lever, link, and

I Figure 5 is an end elevation of the link.

Referring to the drawings by numerals, my in I vention has been shown as applied to a portion of a loom having duplicate side frame members one of which is shown at I, and the usual warp beam 2 rotatably mounted by trunnions, as at. 3, win bearings, as at 4, on a stepped down portion 5 of each frame member I.

The let-off mechanism includes a brake band 6 surrounding one end of said beam 2 for frictional engagement therewith and having a fixed end I secured to the upper edge of the adjacent frame member I by a stud 8, and also having a ree end adapted to beupwardly tensioned in variable degree to frictionally retard rotation of said beam 2 in opposition to the pull exerted V thereagainst by the pay-off of the warp thread thereon and not shown. The free end 9 of said band 6 is tensioned by means including a horizontallydisposed lever I0 fulcrumed adjacent one of its ends on the upper edge I I of the frame member I above said band 6 and beam 2 and by 7. means of a lug I2 on the lower edge thereof seating ina socket I3 provided in said frame member I. Thefulcrumed end of the lever I 0 is provided with a series of notches in its upper edge beyond the lug I2 and as shown at I4. The

free end 9 of the brake band 6- is connected to the fulcrumed end of the lever I0 by means of a Figure 2 is a fragmentary view in perspective of one end of a lever forming part of the said Figure 4 is a view in side elevation of said vertically disposed bolt I5 having a stud I6 at its lower end to which said free end of the brake band 6 is suitably secured, said bolt having a hanger member I I slidably mounted on its upper end and adapted to seat in selected notches I4. The fulcrumed end of the lever I0 may be bifurcated as shown at I4 to receive the bolt I5 therebetween. A nut I8 threaded on to the upper end of the bolt I5 provides for adjusting the free end of the brake band 6 relative to the fulcrumed end of the lever III for a purpose presently seen. The other end of the lever Ifloverhangs the band B and has a free downwardly curved end I9 terminating in a straight portion 20. The straight portion 20 has a plurality of 15 notches 2| formed in the upper edge thereof and spaced longitudinally along said edge.

Removably mounted on the free end [9 of the lever I 0 is a link 22 forming an extension of said end. The link 22 comprises a looped end 23, a hook shaped end 24, and a pair of transverse bars 25 extending across the looped end and spaced apart to correspond with the spacing of the notches 2|. The looped end 23 straddles the free end I9 of said lever I0 and bears upwardly against the under edge thereof, the bars 25 seating in the notches 2I. A second link 26 is hooked over the hooked end 24 of the link 22. A weight 21 is secured in any suitable manner to said links 26 Referring to the operation, by locating the hanger I! in different notches I4 the tension on the brake band B may be varied from the fulcrumed end of the lever as will be understood. Also tension at this end of the lever may be varied by manipulation of the nut I8. The link 22 may be removed and the weight supporting link 26 suspended from the free end of the lever I0 by location in selected notches 2I thereby varying the tension at the free end of the lever I0. Thus 40 it will be seen that the link 22 and the means for mounting the same on the lever 6 provide a very simple means for optionally varying at will the tension of the brake band 6 and supplementing the means at the other end of said lever I0. 45

My invention will, it is believed, he understood from the foregoing description thereof without further explanation.

Manifestly the invention, as described, is susceptible of modification without departing from 50 the inventive concept and right is herein reserved to suchmodifications falling within the scope of the claims appended hereto.

What I claim is:-

1. The combination with a rotatable warp 55 2 beam, of let-off mechanism for controlling rotation thereof comprising a brake band surrounding said beam for frictional engagement therewith and adapted for variable tensioning against said beam, and means for variably tensioning said band including a horizontally disposed fulcrumed lever having a free downwardly curved end provided with notches in the upper edge thereof, a link removably mounted on said free end to form an extension thereof and provided with cross bars seating in said notches and a looped end straddling the free end of said lever and bearing against the under edge thereof, and a weight suspended from the other end of said link.

2. The combination with a rotatable warp beam, of let-01f mechanism for controlling rotation thereof comprising a brake band surrounding said beam for frictional engagement therewith and adapted for variable tensioning against said beam, and means for variably tensioning said band including a horizontally disposed fulcrui'ned lever having a free downwardly curved end provided with notches in the upper edge thereof, a link removably mounted on said free end to form an extension thereof and comprising a looped end and a hook shaped end, said link having cross bars in the looped end thereof seating in said notches and said looped end straddling said free end of the lever and bearing against the under edge thereof, a second link suspended from the hooked shaped end of the first mentioned link, and a weight secured to said second mentioned link. ARTHUR GRENIER. 

